Universal Serial Bus (USB) power-delivery (PD) and Type-C specifications have been released that enable delivery of higher power over new USB cables and connectors. The intent for this technology is to create a universal power plug for laptops, tablets, and so forth that may require more than 5V. The USB-PD specification defines a communication link between source and sink ports connected via a USB-PD cable and connectors. The communication is designed to be half-duplex and packet-based, for example. The packets contain various information that enable the two ports to communicate and negotiate the voltage and current the source port provides to the sink port. The ports can even negotiate to switch roles (Source to Sink and vice versa). The underlying communication in the USB-PD specification is Bi-phase Mark Coding (BMC). This communication occurs independently from normal USB communications that propagate through the same cable (but different wires). The USB-PD communication occurs over a different wire (e.g., the serial communication control (CC) wire) rather than the USB data wires. For USB Type-C cables, up to 15 W can be delivered even without USB-PD messaging by controlling the DC voltage on the CC pin, for example.